Paint.



. FIG

v MERRIWmATI-IER J. WAUGH, or mncomnnnnnasnn.

No Drawing.

To all whom it may concern:

Be it known that I, Mnnmwna'rnnn J WAUGH, a citizen of the UnitedStates, residing at Lincoln, Lancaster county, Ne-

;braska, have invented certain new and useful Improvements in Paints, ofwhich the following is a specification.

This invention relates to improvements in paints for use principally innormal climates, (see 'copending application, Serial No. 568,101) andhas for its essential object to produce a controllable paint coat ofheterogeneous chemical and physical struc ture to withstand the usualtemperature changes of a normal climate, the paint having a maximum ofelasticity andadhesive power, corresponding with that of the expansionand contraction of the'painted surfaceto which it is applied, thusrendering the same climate proof. It is to be understood that referenceto a normal climate is made in contradistinction to humid, dry and aridclimates, where the peculiar weather conditions affect paintsdifferently.

In the practice of this invention I have found it desirable to employ acoarse pigment of chemically stable character and crystalline structure[to furnish paints for capillary action for giving a coat of sufli cientthickness; To fill the spaces between these coarse particles, pigmentsof great' stability. For general exterior use it is necessary to employa hardening coat, because the coat made with sublime white lead or otherlead pigment alone 1s phys cally too soft to withstand abrasion, and itis for this purpose that approximately 18.25% zinc oxid is preferablyemployed. Zinc oxid, when mixed with llnseed 011- and the proper amountof drier, sets and drles more slowly than white lead. Nevertheless, thisdrying continues in the form of progressive oxidation until the surfacebecomes very hard. A comparison between zinc oxid and white lead paintsshows that the PAINT.

Y Specification of Letters Patent. Patented Mar. 21,1911..-

Application filed June 23, 1910. Serial No. 568.531. I

' progressi ve' oxidation which takes place when white lead driesproduces a chalky mixture, while. the reverse is true of zinc oxid,which produces a hard, vitreous surface. Owing, therefore, to thediverse effects of the two pigments. a combination of sublimed whitelead and zinc is for practical purposes desirable.

Approximately 7.7 fibrous magnesium silicate is employed as an inertpigment, since this material has the added physical advantage ofpresenting what is known as a. tooth, which is especially desirable for,repainting, and it is inert as an extender or filler in paint and doesnot combine with any other pigment or vehicle. Fibrous magnesiumsilicate preferably in the form of comparatively long hairlike crystalsof asbestos is desirable, since it tends to remain in suspension and toretain the admixed pigments in suspension therewith. The hairlike crystalsof the asbestos interlace-very much like feathers in a pillow, thusfiuffing the entire mix. Ithas been found that substan-' mately 3%),which preferably'is a matter of selection, the essential being that itshall be crystalline in character, with rather obtuse angles, it havingbeen shown that materials of acute angular fracture, exert too much of aretarding or holding influence on the brush, thus making the labor ofapplication excessive. A blend of fine pigments with moderately angularcrystals is the only mix-so far found which brushes uniformly, and it isto secure a proper modification of this brushing character that thefourth pigment is added thereto. Among the available materials may becitedi calcite (calcium carbonate), tale (a tabular magnesium silicate),china clay or kaolin (hydrated aluminum silicate), barytes (nativebarium sulfate), aragonite and other forms of cal? cium carbonate,plaster of Paris (anhydrous calcium sulfate), dolomite and other mixedcarbonates, feldspar and other complex silicates.

An analysis discloses that one or more pigments of coarse grain areemployed to give a requisite thickness of coat; that two pigments ofextreme and-uniform fineness and grain are employed to give opacity andimpermeability as Well as elasticity and durability; that an addedcrystalline ma terial is utilized to modify brushing; that a selectionof materials is made to avoid dcstructive reaction by the pigments uponthe paint vehicle; and that the same is a mix of non-poisonouscharacter.

Without specifically limiting myself to the foregoing, I claim:

1. In combination with a suitable aint vehicle, a major pigment composedoi approximately 71% sublimed White lead, approximately 18.25% zincoxid,- approximately 7.75% fibrous magnesium silicate, and a fourthpigment, substantially 3%, crystalline in character and of ratherobproximately 182572; zinc oxid, approximately 7 75% fibrous magnesiumsilicate, and approximately 3% of crystallized calcium carbonate ofrather obtuse angular formation for facilitating in application of thepaint.

MERBIWVEATHER J. WAUGH.

Witnesses:

R.-A. \VARREN, RAY C. HALL.

